The present invention relates to optical devices, and more particularly to optical switching and routing devices.
The use of optical fiber for long-distance transmission of voice and/or data is now common. As the demand for data carrying capacity continues to increase, there is a continuing need to utilize the bandwidth of existing fiber-optic cable more efficiently. An established method for increasing the carrying capacity of existing fiber cable is Wavelength Division Multiplexing (WDM) in which multiple information channels are independently transmitted over the same fiber using multiple wavelengths of light. In this practice, each light-wave-propagated information channel corresponds to light within a specific wavelength range or xe2x80x9cband.xe2x80x9d
Because of the increased network traffic resulting from the use of the WDM technique, there is an increasing need for sophisticated optical switching and routing devices which can quickly route numerous channels among various optical communications lines and which can reliably divert network traffic to alternative routes in the event of network failures. Routine network traffic routing requires optical switching devices that can perform reproducibly over many thousands of switching operations. Network failure restoration requires a switching device that must instantaneously perform according to specification after long periods of non-use. The present invention addresses these needs.
The present invention provides a method and apparatus for optical switching devices utilizing a bi-morphic piezoelectric apparatus. The optical switching devices include an arm comprising a piezoelectric material, the arm including a first and a second face and a first and a second end, wherein the first face is opposite to the second face, wherein the first end is opposite to the second end; at least one electrode coupled to the arm for providing a voltage difference between the first and second faces of the arm; a support coupled to the first end of the arm for fixedly supporting the first end; an object with a convex surface coupled to the second end of the arm; an optical element coupled to the second face of the arm capable of deflecting an optical signal traveling therethrough; a first magnet proximately located to the object and to the first face of the arm; and a second magnet proximately located to the object and to the second face of the arm. The optical switching devices include optical switches utilizing a single electro-mechanical apparatuses or a plurality of them in a cascade arrangement, a reversible optical circulator, and a switchable optical channel separator. The optical devices have stable and reproducible operation, high switching speeds, and low sensitivity to slight optical mis-alignments or vibrations. They are of a compact modular design that allows the construction of more complex optical devices through utilization of a cascading arrangement.